[GIFtheory]

Reminds me of this great quotation, which Oksendal places before the preface to his stochastic differential equations book:

We have not succeeded in answering all our problems. The answers we have found only serve to raise a whole set of new questions. In some ways we feel we are as confused as ever, but we believe we are confused on a higher level and about more important things. Posted outside the mathematics reading room, Tromsø University